1. Field of the Invention
The present invention relates to an image processing system, particularly for converting information concerning gradation variation of a television image into a digital code and transmitting it to a computer.
2. Description of the Prior Art
Generally, in carrying out a morphological study on systems, cells or the like, an image observed by a microscope is picked up by a television camera (hereinafter referred to as TV camera), and the optical densities of the various portions of the microscope image, i.e., a gradation of an image of the system or cell, is coded from its video signal and read in a memory of the computer. A pattern having more than a given optical density is counted, or the ratio of optical densities is sought and the like, and any treatment in accordance with the purpose is carried out by a computer, and a result thereof is derived from the computer in general.
In conventional image processing systems, a TV camera scans the image field and the momentary densities are stored for processing in a computer. With a TV camera using the NTSC system, the subdivisions per screen are about 500 in the horizontal direction and about 500 in the vertical direction. The number of subdivisions coded is then 250,000. If the data for the optical density of one image element is composed of six bits, the total data which must be stored by a computer equals 1.5 times 10.sup.6 bits. For this purpose a computer must have a very large memory. Moreover, the time for a single horizontal scan in an NTSC TV camera is 63.5 microseconds. Five hundred image elements are subdivided within this time period. Therefore, the various circuits, such as the sample and hold circuit, the analog-to-digital converters, and the like, which process this information, must have very fast time constants. Accordingly, because of the large memory needed by the computer and the necessary high speed components, conventional image processing systems are expensive.
For performing morphological analyses, such as for analyzing samples of cells, systems, and the like, or non-organic samples such as metallic materials, a more effective analysis might be achieved by noting the sample's special texture, optical density variations, and the like. For example, for observing a live cell, system, or the like, with a microscope, such a sample may be treated optically as a phasic body. A phase difference microscope may observe the image input. In some cases it may be preferable to treat the analysis on the basis of the optical density changes, the number of changes, and the like instead of the optical density of the whole image. However, even when considering the change magnitudues of the optical densities of an optically phasic body, it is necessary to use an expensive and complicated imaging processing system. All the optical densities must be supplied to the computer.
An object of the present invention is to eliminate the aforementioned defects of conventional systems.
Another object of the invention is to furnish improved image processing systems.